Chapter 3: Use Your Brain Power! (42)

1. Which is the oxidant used for purification of drinking water?
→ For purification (actually disinfection) of drinking water on a large scale (such as water supply of cities and towns), Chlorine based oxidants are used 1 Mark
2. Why is potassium permanganate used during cleaning water tanks?
→ Potassium permanganate is a strong oxidising agent. It oxidises certain typs of bacteria. Also, it oxidizes dissolved iron, manganese, and hydrogen sulphide into solid particles that can be easily filtered out of the water tank. Hence, potassium permanganate used during cleaning water tanks. 2 Marks